1. Field of the Invention
The disclosure relates to lamp control, and more particularly, to a lamp control system of a liquid crystal display (LCD) system.
2. Description of related art
Discharge lamps, such as cold cathode fluorescent lamps (CCFLs), are often used as light sources in LCD panels. Generally, the CCFL is driven by an alternating current (AC) signal generated by an inverter circuit.
Two or more pairs of CCFLs are employed to illuminate a large LCD panel for providing sufficient brightness. Thus, the inverter circuit normally has many groups of outputs to generate sufficient AC signals to drive the CCFLs. However, the inverter circuit is usually controlled by one group of input control signals for generating many groups of synchronous and the same output signals.
Referring to FIG. 1, a lamp control system 10 receives a switch signal, and transforms the switch signal to two groups of uniform electrical signals to drive the first lamp 10A and the second lamp 10B simultaneously. The first lamp 10A and the second lamp 10B are controlled by the electrical signals, and are lit or extinguished simultaneously. If there is a requirement to lower brightness of the LCD panel (not shown) employing the lamp control system 10, only one lamp needs to be lit at a time. The lamp control system 10 cannot fully illuminate the LCD panel while lowering its brightness level to conserve power consumption.